Fig. 4.

Colony-forming efficiency of E. coli knockout strains on LB agar. Seven single-gene knockouts were cultured in LB medium, and 0.8 % n-butanol was added at OD₆₆₀ 0.8 followed by incubation for 1.5 h. Then, cell cultures were serially diluted at tenfold gradient, and 10 μL of the diluted solution was spotted onto LB agar for incubation at 37 °C overnight. E. coli JM109 was used as the control